Car door



Aug. 12, 1924.

CAR DOOR mmm w W M W $0 avwmtoz PERCY M. GRIFFIN Patented Aug. 12., 1924.

UNITED STATES PATENT OFFICE.

PERCY M. GRIFFIN, 0F ALBANY, NEW YORK, ASSIG-NOR TO CONSOLIDATED GAB-HEA'I- ING COMPANY, 01? ALBANY, NEW YORK, A CQRPQRATION 01E WEST VIRGINIA.

GAR DOOR.

Application filed April 9, 1924; Serial No. 705,257.

To (ZZZ whom it may concern:

Be it known that I, PERCY M. GRIFFIN, a citizen of the United States, residing at Albany, in the county of Albany and State of New York, have invented certain new.

and useful Improvements in Car Doors, the following being a full, clear, and exact dis closure of the one form of my invention which I at present deem preferable.

For a detailed description of the present form of my invention, reference may be had to the following specification and to the ac companying drawing forming a part thereof, wherein-- Fig. 1 shows a side elevation of my door with the casing for the spring section partly removed, Figure 1 is a front edge view of the door shown in Fig. 1.

Fig. 2 shows the action of the spring mesh.

My invention relates to sliding, motoroperated doors for railways cars, or for other situations where a crowd is admitted periodically and a belated, overhasty person, or one imprisoned by the crowd, is liable to be in the doorway at the time the door closes. For such an emergency it is customary to provide the leading edge of the door with a yielding bar, known as a door-shoe. This shoe is spring-pressed away from the door and, when a passenger or other obstruction is encountered, it will yield towards the door and thereby close an electric circuit to stop or reverse the door motor. Such a door-shoe is not in itself a protection to the passenger, but is relied upon only as a circuit-closing agency for controlling the motor, it being the arrest or reversal of the motor that adequately protects the passenger. For that duty the doorshoe has only a short range of play in order that the control of the motor may take place as quickly as possible; nor does the nature of that duty admit of the shoe exercising any material cushioning effect.

It is the purpose of my invention to provide a safety-edge for such a door that will in itself give all needed protection to the trapped passenger, instead of using it as a circuit-closer for controlling the motor. For that purpose the door must not only have a soft edge but it must be capable of yielding for a considerable distance in the direction of door travel without building up a strong counter pressure of the spring ma terial. This quality must also be uniform along the vertical door edge and at the same time must afford the maximum yield at any local point. Moreover, it must be secured within the narrow space afiorded by the thickness of the door. It. must also involve no excessive stress on the spring employed such as will break the spring or make it take a permanent set. It must also not mar the appearance of the door and must maintain permanently the shape of the door edge and the adjacent surfaces.

To meet these and other requirements for the purpose stated I have devised the arrangement shown in the annexed drawing.

The door as a whole is marked A. To the front edge of the door framework I attach a spring mesh B formed of flat steel bands equal in width to the thickness of the door and bent in a regular sinuous shape. Each band at the crest of succeeding bands is secured alternately to the band in front and the band behind by a rivet. The final band on each side is straight. This spring mesh is preferably six or eight inches in width and is enclosed within a flexible casing, such as a rubber wall G having a lining D of woven fabric. The edges of the rubber sheet and its lining are secured to the framework of the door and drawn taut without materially compressing the spring mesh. The mesh will, however, keep the casing distended and preserve the outlines of the door. The bands composing the spring mesh are extremely thin so that if they were all piled close up against the door they would occupy a space only a frac tion of an inch in thickness. The total normal width of the mesh is largely formed by the air spaces between the successive bands. For that reason the mesh may be compressed laterally a distance nearly equal to its entire normal or distended width. In Fig. 2 the mesh is shown substantially as it would appear when so compressed at one local point by encountering on closing an object E, such, for instance, as a mans arm. In such a case the pressure on object E would not be excessive because the bands are thin and are anchored to one another at points spaced far enough apart to permit easy yielding of the bands. Moreover the resilient spread of the mesh structure is such that it can be drawn in over a wide area centered around the point of local compression. Thus an ample free space is afforded around the ob ect E. In a direction trans verse to the plane of the door the mesh will be stiifbecause of the great Width of the bands in that direction and their riveted relation. l his enables it to preserve the sur face of the door free from deformation under 01 bending under side pressure.

normal conditions and to prevent bulging In cars used for heavy urban traffic, such as in the subways'of large cities, the doors are kept construction has proved adequately stiff and strong to resist that stress and to maintain itself under such hard usage without sagging or loss of shape. At the same time it has the Wide cushioning range I have described in the direction of the doors fore and aft travel.

hat I claim as new and desire to secure by Letters Patent is:

A sliding door having its front edge provided with a spring mesh formed of resilient metal bands disposed in planes trans verse to the plane of the door.

Signed at Albany, county of Albany and State of New York, this 7th day of April, 1924.

PERCY M. GRIFFIN. 

